Dynamo-electric machine



V. A. FYNN. DYNAMO ELCTRIC MACHINE.

.APPLICATION man JULY 2l 1911.

Pand Nov. 23,1920'.

3 SHEETS-SHEET 2'.

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WITNESS mm@ V. A. FYNN'I DYNAMO ELECTRIC MACHINE. APPLlcATloN FILED :ULY2.1911.

1,359,687. Patend Nov. 23, 1920'.

3 SHEETS-SHEET 3.

WITNESS IN'VEN'TUR.

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i UNITED STA inge, forming part o 'rssf VALRE-A. FYNN,- OF ST. LOUIS,MISSOURI, ASSIGNOR TO WAGNER ELECTRIC MANU- FACTUBING COMPANY, OF ST.LOUIS, MISSOURI, A CORPORATION 0F MISSOURI.

DYNAMO-ELECTRIC MACHIE.

1,359,687. Application led vJuly 2,

To all 100km it may concern:

B e it known that LVALREA. FYNN, a subject of the King of England,residing at the city of St..Loui's, State of Missouri, United States ofAmerica, have invented a certain new and useful Dynamo-Electric Machine,of which the following is such a full, clear, and enact description aswili enm able any one siilied in the art to which it ins to laire anduse the same, rei mg had .to the i npanying dra this peciiication.lelify-invenf' tres to alternating current motors or generators and hasfor` its object to automatically vary the excitation of such machines inaccordance with the magnitude of the loa d current and the relation ofsaidl current with espect to the terminal voltage. Y? tors, thisinvention serves --ntrol the v'ss'lien ap it affects Y factor l'ncarrying out my invention part of the excitation of the motor or genernvator dependent on the yphase or magnitude of the load current. To thisend I provide means for lenerating; an E. M. F. the phase of whichalways bears the same relationto the phase of the load currentindependently of any variation between the phase of the load currenttint ofthe terminal volt age. l 'prefer to cause the magnitude of thisE. M. l?. to vary proportionately with n" lie ,load current.` in p tionto mafhincs having @ation I combine this alcurrent-E. M` F. with an M.F. difering in phase and .I impress the reen the alternate rent rectcurrent exciter the excitation for which.l

is provided by the converter.' v

kMy invention will be better understood by reference to the accompanyingdrawings, in which Figure 1 shows the invention as applied to asinglephase alternator. Fig. 5 indicates a modification of Fig. 1. Fig.7 shows the invention as applied to a twophase alternator, and Figs. 2,3. 4 and 6 are explanatory diagrams.

Referring to Fig. 1, the single-phase two- Specification-o1' LettersPatent. I

1917. Serial No. 178,062.'

pole synchronous generator to which the invention is applied 'has anarmature winding 3 located on. the starter and a field structure 4carried by the shaft 2. This field structure is provided with anexcitinv winding 5 connected t0 the slip rings 6,v and usuallyinsulatingly carried by the shaft i. lf-onntcd en this same shaft is thearmadirect current exciter coper- Le stationary field structure 9 .f lieexciting winding 10. The brushes iai, 2b coperating with the armature 8are connected the slip rings 6, 7 by way of stationary brushes. Theshaft 2 provided with a commuted Winding and cooperating brushes 26,27and 31, 32. The field structure 12 cooperating with the arma- 11 isprovided with the exciting wind' in@ 13 included in one of the mains.The .al structnre 53E; perating with the armare 3Q is provided with anexciting wind? ing 29 connected across the terminals of the generator,winding 3. The 'generator 11, 12 is provided with aneutralizing Winding14 adapted to oppose the armature ampere turns. The generator' 30, 28 isprovided with a similar winding 33. T he' armature circuits of these twogenerators are connected in series and to theslip rings 15, 16 of a.rotaryL converter provided on its rot-orwitii a corninuted winding 17with which 'cooperate' the stationary brushes 22, Q3 to which the sliprings 15.` 16 are connected. The stator yof this converter carries avunidirectional exciting winding 18' Connected to the brushes 22, 23 by`way of the adjustable resistance 21, and the two short circuited dampingwindings 19, 20. The direct current brushes 22, 23 are connested' to theexciting winding 10 of the direct-current eXcitervS, 9. One pole of thisexciting winding 10 is also connected `to the brush 25 of the exciterwhile the two-way switch 41 is interposed between the otherpole of thewinding 10 and the brush 23 of the lconverter. When the switch 41occupies the position shown in Fig. 1 then the winding 10 is connectedto the brushes S32, 23 of the converter. When swit/.h 41 is moved to thecontact 51, then the winding 1Q is connected to the brushes 24, 25.

The operation of the machine as a synchronous generator is .somewhat asfollows: Assuming ythe machine to be running on tion produced by 13. Fora unity open circuit, with a voltage e at its -terminals, then all ofthe unidirectional exc1tat1on produced bythe winding 5 will be due tothe E. M. F. e generated in the armature 30 by rotation through thealternating field due to the exciting winding 29. The armature 11generates no E. M. F. because there is no current through the excitingwindln 13, and e is therefore zero. The E. M. c" is impressed on sliprin S15, 16 of the converter, a direct current M. F. proportional to ein magnitude appears at the commutator brushes 22, 23, and is impressedon the exciting winding 10 of the direct current exciter and produces atthe commutator brushes 24;, 25 thereof a direct current E. M. F.proportional to e 'and therefore a unidirectional excitation of thesynchronous generator which is also proportional to e. The phase of e isthe same as that of the magnetization produced by 29 and lags bypractically 90 degrees behind the phase of e, because the E. M. e is1mpressed on the inductive windlng 29 and produces therein a. currentand a magnetization laggin by about 90 degrees behlnd e. The E. M.generated in"30 and appearing at thebrushes 31, 32, is always in phasewith the magnetization (produced b 29 and therefore in phase qua raturewit e. Its magnitude depends onthe magnitude of the magnetizationproduced by 29 and on the speed at which the armature 30 revolves. Itsperiodicity is independent of the speed of rotation and is the same asthe periodicity of the exciting flux due to 29. upposing, now, that thealternator is caused to deliver a current in phase with its terminalvolta e, this load current z', circulating through t e exciting winding13, will produce a magnetization practically in phase with it, andtherefore with e, with the result that an alternating E. M. F. e willappear at the brushes 26, 27, the phase and periodicit of which will bethe same as that of the oad current z', and the magnitude of which willdepend on the speed of rotation of the armature 11 and on the magnitudeof the excitapower factor load,`e will be in phase wlth e because z' isthen in phase with e, and will combine with e as ,shown in Fig. 2, theresultant E being larger than e and displaced in phase therefrom. Thephase of the resultant will have n0 influence on the excitation of thesynchronous generator, but its magnitude will. This increase in theexcitation of the synchronous generator, for an increase of a unitypower factor load. will tend to compound the generator. Should thenature of the load change and cause the generator current to lag behindits terminal voltage. then e will lag by a corresponding angle behind e,as shown in Fig. 3, and will more nearly approach the phase of e.

The resultant E of e and e will, under those circumstances, be very muchgreater than in the case of unity power factor, even though themagnitude of 11 has remained unchanged, thus making up for thedemagnetizing effect of fa lagginer load current. This is .clearly shownin ig. 3. Should the load current lead the terminal E. M. F. of thesynchronous generator, then e vwill lead e and theresultant E impressedon the alternate current side of the rotary converter will be very muchsmaller, as clearly appears from Fig. 4, thus reducing theunidirectional magnetization of the synchronous generator in proportionto the magnetizing effect of a leadin load current.

A convenient Way o initiating the operation of such an alternator is toopen switch 53 and then move switch 41 to point 51, thus making theexciter 8, 9 self exciting and bringing the terminal voltage of thesynchronous alternator to the desired value,

' for instance b means of the adjustable resistance 52. t is nextnecessary to bring the converter up to speed in some known manner and toclose switch 53. When the voltage at the converter brushes 22, 23 isabout the same as that impressed on the winding 10 of the exciter and isof the proper direction, then switch 41 can be moved into the positionshown in Fig. l, thus completing all the normal operating connections.

The successful operation of the arrangement shown in Fig. 1 depends onthe constanc of the hase relation between the loa current M. F. e andthe load current z', and also on the availability of a secondalternating E. M. F. dis laced in phase from the load current E. F.preferably by 90 degrees when the load current is in phase with theterminal voltage of the alternator. In order to carry out this inventionsuccessfully, it is not necessary that the load current E. M. F. be ofsam'e phase as z'; it may have any desired phase relation with respectto z', so'long as this relation remains constant throughout any hasevariations of i. The phase of the M. F. e should in all cases bereferably so chosen as to be in hase ua rature with the load current M.F. at the time when the load current is in phase with *the terminal E,M. F.

'E M. F. of same phase as the terminal voltage.

In Fig. 5 the auxiliary dynamo 30, 28 of Fig. 1 is dispensed with andreplaced by the shunt transformer 57 connected across the mains 58, 59.The dynamo 11, 12 has an exciting winding 13 connected in circuit withthe main 59, short -circuit'ed, brushes 26, 27 displaced by 90electrical degrees from the axis of the exciting winding 13, and otherbrushes 54, 55 coaxial with they exciting winding 13 and with theneutralizing winding 56 with which they are connected in series. Theload current E. M. F. e is generated at these brushes 54, 55 and isconnectedin series with the auxiliaryE. M. F. e derived from thesecondaryI o shunt transformer 57. In other respects the arran mentshown .in Fig. 5 is Identical with t at of Fig. 1. s

Fig. 6 yshows the phase relations of the load current and the various E.M. F.s in Fig. 5v for the case of phase coincidence between the loadcurrent i and the terminal E. M. F. e of the synchronous generator ormotor, 3, duced by the winding 13 in the 12, is in phase with lz', andin t is case also in phase with t-he terminal voltage e. The voltagegenerated at the brushes 26, 27 by rotation of the armature 11 is inphase withl z'. The current due to t,k at voltage and circulatingthrouvh the armature 11 along the axis 26, 27, ags by about 90 degreesbehind 'z' and produces a magnetzationof practically the same phasealong the axis 26, 27. By rotation of the armature 11 in. this lastmagnetization,' there is generated an E. M. l?. e in phase glenerator11,

with this magnetization-and therefore lacfgnv by about 90 de rees behindz'. The F.s e and e of ig.- 5 have therefore under all circumstancesexactly the same phase each other as the correspondin E. Ml F.s ofFig'. 1. But in Fig. 5 e 1s always in phase quadrature with the load.current z', instead of always being in phase with it as in Fig. 1.

Fig. 7 unidirectional excitation of which 1is `made dependent on two E.M. F.s. Each of these E. M. F.s is the vectorial sum of two alternatingE. M. F.s, one ofwhich is in phase with the terminal voltage of onephase while the other is in phase with the load current in the otherphase. The resultants are impressed on the alternating current side ofarotary converter the direct current side of which controls theexcitation of the direct current exciter supplying the synchronousalternator or motor. The stationary armature of the two pole synchronousmachine carries a winding 3 tapped at four e uidistant points angenerating the equal ut phase displaced, E. M. F.s d and e. The eldstructure 4 is carried b and is provided with a uniirectional ex# citingwindin 5 connected to the slip rings 6 and 7 usually insulatinglysupported by the shaft 2. his same shaft carries' the armature 8 of thedirect current exciter,

4. The magnetization pro-- relation to shows a two-phase alternator thethe shaft 2 the brushes `24, 25 of which are connected to the slprings6, 7, by way of stationary brushes. The citer carries the winding 10,one end of whlch is permanently connected to the brush field structure 9of this exi 25 cooperating with the armature Sand to i the directcurrent brush 23 of the converter.

The lother end of the winding can be coni nected either to the brush 24of the exciter,-l

erator carries an exciting winding 13 connected to the secondary of theseries transd former 43 the primary of which is' included in the phase eof the synchronous generator. It also carries an exciting winding 47connected to the secondary of the lseries transformer 42 the primary ofwhich is included in the phase d ofthe synchronous generator. Thebrushes 26, 27 are displaced `by 90 electrical degrees from the excitingwinding 13 and connected in series with the neutralizing winding 14,said winding being adapted to neutralize the armature reaction along theaxis 26, 27. The E. M. F. e', appearing at the terminals ofthis'circuit, is always in hase with the load current of the phase e.

he brushes 49, 5() are displaced by 90 electrical degrees with respectto the axis of the exciting winding 47 and are connected in series withtheneutralizing winding 48 adapted to annul the armature reaction alongthe axis 49, 50. The E. M. F. d,`ap pear-ing at the terminalsofthiscircuit, is always in phase with the load current of phase, d of thesynchronous generator. The shunt transformer 44 is connected acrossphase e, and the E. M. F. e appearing at the terminals of its secondarywinding is in phase with the terminal E. M. F. of phase e. f

d. The rotorof the two-pole converter carries a commuted winding 17connected at four equidistant oints to the slip rings 15, 60, 16, 61.Brus es 22, 23 cooperate with this commuted winding and are connected tothe stator winding 18, the axis of' whichk is displaced by 90 electricaldegrees from the brush axis. 22, 23. The stator also can ries twodisplaced damping windings 19, 20. The slip ring 16 is connected bymeans of a stationary brush to the neutralizing winding 48, the brush50, the commuted winding 11, the brush 49, the secondary of the shunttransformer 44, and the slip ring 15 through the brush coperatingtherewith.

The slipring 61 is connectedto the `neutralizing Winding 14, thebrush26, the comniuted Winding 11, the brush 27, the secondary of the shunttransformer 45, and the slip ring 60. In this Way the vectorial sum ofthe E. M. F.s e and d is impressed on the axis G0. 61 of the rotaryconverter While the vectorial sum of the E. M. F.s d and c is impressedontlie axis 15, 16 of this converter, which is displaced by 90electrical degrees from the first.

The'operation of this alternator is the same as that of the machineshownin'Fig. 1. In order to` initiate the excitation of the synchronousgenerator, it is preferred to move switch 41 to point 51. As soon as anappreciable E. M. F; appearsat the terminals ofthe generator winding 3,thepolyphase converter will start and reach synchronism. YVhen asufcientexcitation has been produced, switch 41 can be moved to 63, thusconnecting the .Windinfr 10 to the brushes 22, 23 or" the converter. TheM.

Ffs e" and d will always coincide in phaseY the tren-4 with the terminalE. li/i. F.s of

erator.. rEhe FJJM. -F.s c and d" v lel- Wafs bein phase with the loadcui j y the tivo-phases. .ifn order to see new the unid'ctionalexcitation@1 che synchronous shown in 'i varies with the load andvarying power factor Aof load, it is only toobserve the variation of thema ..de oi the vectorial sum nii-ol aiid'ev.- a e andk d Sider` d and e,yen that in d taires fe or e v enthat in if d" taires the ple-.ce ofer'. rring more particularly 'tc is apparent from Figs. 2, 3 and itmagnitude ot c must be Sele@ ed to pr` the necessary no-load ex Imagnitude of e is chose the desired termina power factor load, then thedirectly magnetizing eiiect of the armature re or lagging power factornot r-lpixilkierly taken care of as to magnitude by an bi. M.

e ot same value. To atleast partly overcome this diiiiculty it isdesirable to compound tlie converter in some lrnoivn Way, for instanceby means of impedance in the slip ring circuit.l A simple Way to achievethis end is to under-neutralize the dynamos 11, 12 or 28, 30.

Having .fully described my invention. what l claim as new and desire tosecure byV Letters Patent of the United States is:

. 1. -ln combination. an alternating current dynamo electric machinehaving an exciting Winding, means for .producing an alternating currentE. M. F. having a constant phase-relation to the load current ot thedynamo electric machine, means for producing a second alternatingcurrent E. M. F. having aconstant phase relation to the terminal voltageof the dynamo electric machine, and meansfor utilizing the resultant ofsaid E. M. F.s lto vary the excitation of the dynamo electric machine. i

2. In combination, an alternating current dynamo'electi'ic machinehaving an exciting winding, means for producing an alternating currentE. M. F. having a constant phase relation to the load current of thedynamo electric machine, means for producing a .second alternatingcurrent E. M. F. having a constant phase relation to the terminalvoltage of the dynamo electric machine, and

`mea-ns for varying lthe excitation ol' the dynamo electric machine inresponse to variations in the-magnitude of the resultant oi' said E. M.F.s.

- In combination, an alternating current dynamo electric machine havingan exciting Winding', on auxiliary lalternating current gen ttorrim'orproducingl an alternating eurrent E. M.-

`having a constant phase relation to the load current of the dynamoelectric machine, meansfor producing a second E. M. F..having a constantphase relation to the terminal voltage of the dynamo electric machine,and means for utilizing the resultantot said -E. M. F.s to vary theexcitation of the dynamo electric machine.

LL. In combination. an alternating current dynamo electric machinehaving an exciting Winding, means for producing an alternatiner current.E. -M. F. constantly in phase quadrature to the load current of thedynamo electric machine, and means for utilining said M. F. to vary theexcitation of the dynamo electric machine.

5. In combination, an alternating current dynamo electric machinehavingan exciting Winding, means for deriving two alternatingk current E. M;F.s, one of which has a constant phase relation to the load current ofthe dynamo electric machine, said E. M. F. also being'in phasequadrature With the other E. M. F. when the load current is in phasewith the terminal E. M. F. of the dynamo electric machine, and means forutilizing the resultant of said E. M.`F.s to

vary the excitation of the dynamo electric machine.

6. In combination, an alternating current dynamo electric machine havingan exciting Winding, means for' deriving two alteinating current E. M.F.s one of which has a constant phase Vrelation to the load current ofthe dynamo electric machine, the phases of said E. M. F.s when the loadcurrent is in phase With the terminal E. M. F. being such` that one ofthem is in phase with the terminal E. M. F. and the other in quadraturethereto, and means for utilizingl the resultant of said E. M. F.s tovary the excitation of the dynamo electric machine.

7 In combination, an alternating current dynamo electric machine havingan exciting winding, means for producing an alternating current E. M. F.constantly in phase quadrature with the loadl current of the dynamoelectric machine, means for producing a second alternating current E. M.F. of the same phase as the terminal voltage of the d namo electricmachine, and means for utilizing the resultant of said E. M. F.s to varythe excitation of the dynamo electric machine.`

8. In combination, an alternating current dynamo electric machine havingan exciting winding, a direct current exciting dynamo in circuit withsaid exciting winding, an auxiliary alternating current generator havingits field winding in series relation with the dynamo electric machine, arotary converter having its alternating current side\connectedv incircuit with the auxiliary generator, and

its direct current side connected to the directl current dynamo.

,9. In combination, an alternating current y dynamoA electric machinehaving an exciting Winding, means for deriving two alternating currentE. M. F.s, one of which is always in phase quadrature with the loadcurrent of the dynamo electric machine, said E. M. F.

, erator, means for aplllying to said last named also being in phasequadrature with the other E. M. when the load current is in phase withthe terminal E. M. F. of the dynamo electric machine, and means forutilizing the resultant of said E. M. F.s to vary the excitation of thedynamo electric machine.

10. In combination, an alternating current dynamo electric machinehaving an exciting Winding, a direct current exciting dynamo in circuitwith said exciting winding, an auxiliary alternating current generatorhaving its field winding in series relation with the dynamo electricmachine, a rotary converter r.

connected in circuit with the auxiliary gencircuit a second E. F. whosephase is in quadrature with the E. M. F.vproduced by the auxiliaryalternating current generator, when the load current ofthe dynamoelectric machine is in phase with the terminal E. M. F. thereof, andmeans connecting the direct current side of the rotary converter to thedirect current dynamo.

11. In combination, an alternating current dynamo electric machinehaving an exciting winding, a direct current exciting dynamo in circuitwith said exciting Winding, a rotary converter, an auxiliary alternatingcurrent generator having its field Winding in series relation with thedynamo electric machine and having its armature provided with two setsof brushes displaced by 90 electrical degrees from each other, one ofsaid sets of brushes being in the axis of the field winding and incircuit with the rotary converter and tthe other set of brushes beingshort-circuited,

' and in circuit with the rotary converter and the other set of brushesbeing short-circuited,

means for applying to the circuit including the rotary converter and theauxiliary alternating current enerator a second alternatcurrent E. beinin phase quadrature with the E. M. F. pro uced by the auxiliarygenerator when the load current of the dynamo electric machine is inphase with the terminal E. M. F. thereof, and means connecting thedirect current side of the rotary converter to the direct currentdynamo. i

. F., said second E. M. F;

In testimony whereof I have hereunto set i my hand and aiiixedmy seal.

VALRE A. FYNN. [1.. 5.]

